Electric curling-iron.



O. P. MADSBN.

ELEGTRIG GURLING IRON.

APPLICATION FILED MAR. 22, 1911.

Patented Feb. 27,1912

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UNITED STATES PATENT; OFFICE.

CHARLES I. MADSEN, or cmcaso, ILLINOIS, ASSIGNOR TO rELouzE" ELEcrItIc HEATER oo., or CHICAGO, ILLINOIS, A CORPORATION or ILLINOIS.

ELECTRIC CURLING-IRON.

Specification of Letters Patent.

Application filed March 22, 1911. Serial No. 616,256;

To all whom it may concern:

Be it known that I, CHARLES MADSEN,

a citizen of the United States of America,

' ment.

and a resident of Chicago, county of Cook, State of Illinois, have invented certain new and useful Improvements in Electrlc Curling-Irons, of which the following s a speclfication.

The main objects of this invention are to provide a new and improved electric curling iron structure which will operate at high efiiciency; to provide a structure by means of which an operating temperature can be quickly reached; to provide a structure, 1n which the emissivity will equal the energy inflow at a predetermined temperature; and to provide a structure in which there may be relative rotation between the heating element and the curling element.

I am aware that curling irons of tubular form have been heated electrically, and do not therefore claim this as new. A grave defect, however, has been that the storage capacity has been so great and the power of heat transfer in the iron so slow that it has required. an enormous relative quantity of energy to bring the iron up to working conditions. When, however, such a working temperature has been reached, the heat stored, together with that generated by the continuous supplying of additional energy soon brings the temperature to a dangerous point. Such an iron would be dangerous not only because it would require eternal vigilance on the part of the operator to avoid burning the hair, but should it be laid down for a few minutes, itwould readily set fire to any organic.

matter with which it might have contact.

A specific construction embodying my present invention is illustrated in the accompanying drawings, in which Figure 1 is a sectional view of a curling iron as assembled ready for attachment. Fig. 2 is a perspective of the heating ele- Fig. 3 is a cross section of the heating element on the line AA of Fig. 2.

In the construction shown, the heater 1 has a minimum quantity of material and by arrangement of the shape of the heater and its relation to the casing 2 of the iron, there is a minimum lag in the heating effect. To accomplish this, I use a heater consisting of a very thin tube 3. On the out-side of this tube 3 is wound a wire 4 in progressive spiral. The tube 3 is only slightly smaller in diameter than the inner diameter of the metalliccasing 2 into which it goes. I do not put any insulating material or compound over the wire 4, as I do not wish to transfer the heat by conduct-ion, but instead obtain a much more rapid transfer by radiation. The tube is therefore provided with loose fitting concentric rims or shoulders 5, or is made larger in diameter at each end of the winding. When this heater 1 is in place, there will therefore be a very small air space between the heat generating wire 4 and the metallic tube 2. Th resistance wire 4 operates at a high temperature. The heat therefore passes almost instantly through the small air space into the outer metal casing 2. The relationship between the emissivity' of this outer tube and of the energy 1 is, at this temperature, the emissivity of the tube is equal to the energy inflow consumed by the heater 1. It is found that 212 to 250 is sufficient to perform the operation of curling. Since the mass of the contents of the casing 2 is extremely small, the heating effect is almost instantaneous For making this tube 3, Iprefer to use pure asbestos paper. This may be used plain, or may be slightly impregnated with a non-hygroscopic. compound. It is possible, however, to use a tube made of other substances than asbestoS, for instance, ordinary paper, or vulcanized fiber chemically treated would answer. Also the tube may be built up of mica splittings.

The essential spirit of my invention is the use of a very light tube having on its outer surface a winding which is not covered, but is so arranged that it cannot touch the metallic tube. Into one end of this tube I fasten a terminal block 6 which may be made of a molded insulating compound or preferably of vulcanized fiber. This block carries two binding posts 7. One lead from the winding extends along the outside of the tube to onebinding post, and the other lead from the winding extends through the tube 3 and is connected to the other binding post or screw 7 This block also has in its farther end one or two holes 8, through which the flexible conducting cord 9 is tied.

The terminals of the conducting cord 9 are in turn connected with the binding posts 7. This constitutes a complete heater 1, which is rotatable within the casing 2 and may be readily removed from the curling iron.

The curling iron body consists of av casing 2, preferably made of cold rolled steel pointed at its outer end. Near its base or open end 10, it is provided with a yoke 11 partially surrounding its circumference, and supplied with two ears 12. Hinged to these cars 12 and adapted to operate thereon is a shield 13 such as is commonly used on ordinary curling irons. This shield is provided with an operating button 14 at one end and adapted to fit the tube throughout its length. The handle 15 is prevented from turning by a prong 11 on the yoke 11 which projects into it. The handle 15 has a hole throughout its length concentric with the hole into' which the tube is inserted. Into this hole is inserted the heater. The parts are so adjusted that the terminal block 6 will stand within the open end of the hole in the wood handle. Through a side of the wood handle near its open end, is a small ",hole 16. 'A small screw 17 threaded in this hole coacts with a shoulder 18 on the terminal block 6 to prevent the heater 1 from slipping from the casing 2. In case the screw is advanced so as 'to cut into the terminal block 6, it will act as a set screw and prevent relative rotation between the heating element and the'casing.

In an article of this kind, trouble is often caused by kinking and twisting the con ducting cord in the operation of curling. Swiveled' conductor connect-ions have been used, but are undesirable because of added cost and complications of extra parts. In the structure shown, kinking or twisting of the cord is avoided by allowing the curling iron frame as a whole to revolve about the heating element and the conducting cord as insulating tube, resistance wire woun it will be understood that numerous details of the construction shown may be altered or 1. An electric curler, comprising a casing a heating element, and in-leading electrical conductors tied to said heating element, said heating element-and conductors being rotatable in said casing.

2. An electric curler, comprising a heating element, flexible conductors secured to said heating element, and a casing rotatable about said heat-ing element and conductors.

3. In an electric'curler, the combination of a casing and a heating element includin an on said tube, a terminal block secured to said tube and having suitable electrical con- 1 nectors, and means for tying in conductors on said terminal block, said heating element and block being rotatably mounted within said casing.

4. In an electric curler, the combination of a casing and aheating element including an asbestos paper tube, resistance wire Wound on said. tube, a terminal block secured to said tube and having suitable electrical connectors, and means for tying in conductors on said terminal block, said heating element and block being rotatably mounted within said casing.

5. In an electric curler, the combination of a casing, a hollow handle'rigidly mounted on said casing, a heating element mounted in said casing, shoulders .on said heating element coacting with said casing, said shoulders being fitted to permit relative rotation between said heating element and said casing.

Signed at Chicago this 20th day of March 1911.

CHARLES P. MADSEN. Witnesses:

I MARY M. DILLMAN,

PHILIP B. WOODWORTH. 

